In the prior art, there is known a front fork for suspending a front wheel of a saddle type vehicle such as a two-wheel vehicle or a three-wheel vehicle, the front fork including a cylinder, a piston slidably inserted into the cylinder to partition the cylinder into an extension-side chamber and a contraction-side chamber, and a free piston having one end connected to the piston and the other end extending outward of the cylinder. In this front fork, a damping force is generated by virtue of a differential pressure between the extension-side chamber and the contraction-side chamber.
For example, in a front fork discussed in JP 2006-329372 A, a pressure chamber filled with a hydraulic fluid and a reservoir enclosed with a hydraulic fluid and a gas are partitioned by the free piston, and the free piston is biased to the pressure chamber side by a pressurizing spring. In this configuration, the pressure chamber is pressurized by the free piston and the pressurizing spring, so that it is possible to obtain excellent damping force responsiveness.